package month1;

public class NumIslands200_06 {
    public static void main(String[] args) {
        System.out.println(numIslands(new char[][]{{'1', '1', '1', '1', '0'}, {'1', '1', '0', '1', '0'}, {'1', '1', '0', '0', '0'}, {'0', '0', '0', '0', '0'}}));
    }

    /**
     * 渲染函数
     * @param grid
     * @return
     */
    static int numIslands(char[][] grid) {
        int ret = 0;
        for (int i = 0; i < grid.length; ++i) {
            for (int j = 0; j < grid[0].length; ++j) {
                if (grid[i][j] == '1') {
                    dfs(grid, i, j);
                    ret++;
                }
            }
        }
        return ret;
    }

    static void dfs(char[][] grid, int i, int j) {
        if (i < 0 || i >= grid.length || j < 0 || j >= grid[0].length || grid[i][j] == '0') {
            return;
        }
        grid[i][j] = '0';
        dfs(grid, i, j + 1);
        dfs(grid, i, j - 1);
        dfs(grid, i - 1, j);
        dfs(grid, i + 1, j);
    }
}


